Rotor assemblies and related control systems

Abstract

In one aspect, a rotor assembly includes a hub and a plurality of rotor blades; at least one blade root actuator configured to adjust at least one of the plurality of rotor blades independently of the other rotor blades to accommodate forces on the aircraft; and at least one controller couplable to the at least one blade root actuator and configured to send signals to the at least one blade root actuator to enable adjustment of the at least one of the plurality of rotor blades. In another embodiment, at least one blade flap is associated with a rotor blade can be actuated to adjust the shape of the rotor blade. In some embodiments, there are methods and systems incorporating at least one of the root blade actuator and the blade flap for stabilizing a tiltrotor aircraft by counteracting destabilizing forces on at least one rotor blade.

What is claimed is: 
     
         1 . A rotor assembly comprising:
 a hub configured to be coupled to an aircraft;   a plurality of rotor blades configured to extend laterally from the hub and to rotate about the hub, each of the rotor blades comprising an inboard end and an outboard end;   at least one blade root actuator configured to adjust at least one of the plurality of rotor blades independently of the other rotor blades to accommodate forces on the aircraft; and   at least one controller couplable to the at least one blade root actuator and configured to send a signal to the at least one blade root actuator to enable adjustment of the at least one of the plurality of rotor blades.   
     
     
         2 . The rotor assembly of  claim 1 , further comprising:
 at least one sensor configured to detect at least one of rotor whirl, rotor flapping, and wing bending;   wherein the at least one controller is configured to enable the at least one root actuator to adjust the at least one rotor blade independently of the other rotor blades in response to detections of the at least one sensor.   
     
     
         3 . The rotor assembly of  claim 1 , wherein the at least one controller is configured to enable the at least one root actuator to adjust the at least one rotor blade with a non-sinusoidal command signal. 
     
     
         4 . The rotor assembly of  claim 1 , wherein the assembly comprises:
 at least one blade root actuator configured to adjust each of the plurality of rotor blades independently of the other rotor blades to accommodate forces on the aircraft;   wherein the at least one controller is couplable to each blade root actuator and configured to send a signal to each blade root actuator to enable adjustment of each of the plurality of rotor blades.   
     
     
         5 . The rotor assembly of  claim 4 , wherein the at least one controller is configured to enable each blade root actuator to adjust each rotor blade with a command signal, wherein the command signal is a non-sinusoidal command signal, and wherein the command signal for each rotor blade is different from the other rotor blades. 
     
     
         6 . The rotor assembly of  claim 1 , further comprising:
 at least one blade flap couplable to a trailing edge of at least one of the plurality of rotor blades; and   at least one blade flap actuator couplable to the at least one blade flap and configured to adjust the at least one blade flap to accommodate forces on the aircraft;   wherein the at least one controller is couplable to the at least one blade flap actuator and configured to enable the blade flap actuator to adjust the at least one blade flap independently of the other blade flaps, if any.   
     
     
         7 . A rotor assembly comprising:
 a hub configured to be coupled to an aircraft;   a plurality of rotor blades configured to extend laterally from the hub and to rotate about the hub, each of the rotor blades comprising an inboard end, an outboard end, a leading edge, and a trailing edge;   at least one blade flap couplable to the trailing edge of at least one of the plurality of rotor blades;   at least one blade flap actuator couplable to the at least one blade flap and configured to adjust the at least one blade flap to accommodate forces on the aircraft; and   at least one controller couplable to the at least one blade flap actuator and configured to enable the blade flap actuator to adjust the at least one blade flap independently of the other blade flaps, if any.   
     
     
         8 . The rotor assembly of  claim 7 , further comprising:
 at least one sensor configured to detect at least one of rotor whirl, rotor flapping, and wing bending;   wherein the at least one controller is configured to enable the at least one blade flap actuator to adjust the at least one blade flap independently of the other blade flaps, if any, in response to detections of the at least one sensor.   
     
     
         9 . The rotor assembly of  claim 7 , wherein the at least one controller is configured to enable the at least one blade flap actuator to adjust at least one of blade pitch and blade flapping position by adjusting the at least one blade flap. 
     
     
         10 . The rotor assembly of  claim 7 , wherein the assembly comprises at least one blade flap couplable to the outboard end of at least one of the plurality of rotor blades. 
     
     
         11 . The rotor assembly of  claim 7 , wherein the assembly comprises:
 at least one blade flap couplable to each of the plurality of rotor blades; and   at least one blade flap actuator couplable to each blade flap and configured to adjust the at least one blade flap to accommodate forces on the aircraft;   wherein the at least one controller is couplable to the at least one blade flap actuator and configured to enable adjustment of each blade flap independently of the other blade flaps.   
     
     
         12 . The rotor assembly of  claim 11 , wherein the at least one controller is configured to enable the at least one blade flap actuator to adjust each blade flap with a command signal, and wherein the command signal for each blade flap is different from the other blade flaps. 
     
     
         13 . The rotor assembly of  claim 7 , further comprising:
 at least one blade root actuator configured to adjust at least one of the plurality of rotor blades independently of the other rotor blades to accommodate forces on the aircraft;   wherein the at least one controller is couplable to the at least one blade root actuator and configured to send a signal to the at least one blade root actuator to enable adjustment of the at least one of the plurality of rotor blades.   
     
     
         14 . A method for stabilizing a tiltrotor aircraft during operation, the tiltrotor aircraft including a plurality of rotor blades, comprising:
 identifying, with a sensor, forces on an aircraft;   determining, by a controller, a first desired stability value for a first rotor blade based on at least in part on the forces on the aircraft;   generating a first command signal corresponding to the first desired stability value to a first actuator associated with the first rotor blade; and   adjusting, with the first actuator, the first rotor blade independently of the other rotor blades to achieve the first desired stability value.   
     
     
         15 . The method of  claim 14 , wherein the first actuator comprises a blade root actuator, and the adjusting step comprises adjusting the pitch of the first rotor blade. 
     
     
         16 . The method of  claim 14 , wherein the first actuator comprises a flap actuator, and the adjusting step comprises adjusting a flap associated with the first rotor blade. 
     
     
         17 . The method of  claim 14 , wherein the first command signal is non-sinusoidal. 
     
     
         18 . The method of  claim 14 , further comprising:
 determining, by a controller, a second desired stability value for a second rotor blade based on at least in part on the forces on the aircraft;   generating a second command signal corresponding to the second desired stability value to a second actuator associated with the second rotor blade; and   adjusting, with the second actuator, the second rotor blade independently of the other rotor blades to achieve the second desired stability value;   wherein the first command signal and the second command signal are different.   
     
     
         19 . The method of  claim 18 , wherein the second actuator comprises a blade root actuator, and the adjusting step comprises adjusting the pitch of the second rotor blade. 
     
     
         20 . The method of  claim 18 , wherein the second actuator comprises a flap actuator, and the adjusting step comprises adjusting a flap associated with the second rotor blade. 
     
     
         21 . A stabilization system for a tiltrotor aircraft including a plurality of rotor blades, comprising:
 a processor; and   a non-transitory computer-readable medium comprising one or more processor-executable components, the one or more processor-executable components configured to be executed by the processor to cause the system to:
 identify, with a sensor, forces on the tiltrotor aircraft; 
 determine a first desired stability value for a first rotor blade based at least in part on the forces on the tiltrotor aircraft; 
 generate a first command signal corresponding to the first desired stability value to a first actuator to cause the first actuator to adjust a portion of a first rotor blade independently of the other rotor blades; 
 determine a second desired stability value for a second rotor blade based at least in part on the forces on the tiltrotor aircraft; and 
 generate a second command signal corresponding to the second desired stability value to a second actuator to cause the second actuator to adjust a portion of the second rotor blade independently of the other rotor blades; 
 wherein the first and second command signal are different. 
   
     
     
         22 . The system of  claim 21 , wherein the first and second command signals are non-sinusoidal.